Neutral particle beam processing apparatus

ABSTRACT

A neutral particle beam processing apparatus comprises a process gas inlet port ( 11 ) for introducing a process gas into a vacuum chamber ( 1 ), a plasma generating chamber ( 2 ) for generating positive ions and electrons from the introduced process gas, and a negative ion generating chamber ( 3 ) for attaching electrons generated in the plasma generating chamber to the residual gas to generate negative ions. The neutral particle beam processing apparatus further comprises an ion extracting portion ( 4 ) for extracting the positive ions or the negative ions and accelerating the positive ions or the negative ions in a predetermined direction, and a neutralizing chamber ( 5 ) for neutralizing an ion beam generated by the ion extracting portion ( 4 ) to generate a neutral particle beam. The neutral particle beam generated in the neutralizing chamber ( 5 ) is applied to a workpiece (X).

TECHNICAL FIELD

[0001] The present invention relates to a neutral particle beamprocessing apparatus, and more particularly to a neutral particle beamprocessing apparatus for generating a highly directional and highlydense neutral particle beam from a high-density plasma and processing aworkpiece with the generated neutral particle beam.

BACKGROUND ART

[0002] In recent years, semiconductor integrated circuits, informationstorage media such as hard disks, micromachines, and the like have beenprocessed in highly fine patterns. In the fields of processing suchworkpieces, attention has been attracted to the use of an energetic beamsuch as a high-density neutral particle beam or a high-density ion beamwhich is highly linear, i.e., highly directional, and has a relativelylarge beam diameter. For example, the energetic beam is applied to aworkpiece for depositing a film thereon or etching the workpiece.

[0003] As beam sources of such energetic beams, there have been usedbeam generators which generate various kinds of beams including apositive ion beam, a negative ion beam, a neutral particle beam, and aradical beam. The positive ion beam, the negative ion beam, the neutralparticle beam, or the radical beam is applied to a desired area of aworkpiece from the beam source, for thereby locally depositing a film onthe workpiece, etching the workpiece, modifying the surface of theworkpiece, or joining or bonding parts of the workpiece.

[0004] When charged particles are applied to a workpiece such as anextremely thin silicon oxide film for semiconductor integrated circuits,a dielectric breakdown may be caused on the workpiece. However, aneutral particle beam having no electric charges but having a largetranslational energy is unlikely to damage a workpiece. Therefore, ithas been expected to apply such a neutral particle beam to fineprocesses.

[0005] As a beam source of such a neutral particle beam, there has beenknown a beam generator which generates a negative ion beam from a plasmaand detaches electrons from the negative ion beam by electron impact forthereby neutralizing the negative ion beam. This neutral particle beamgenerator comprises a neutralizing chamber having a filament therein.Thermoelectrons produced by the filament are trapped in the neutralizingchamber to generate an electron cloud having a high energy. The negativeion beam which has been focused with an electrostatic lens is introducedinto the neutralizing chamber and neutralized by detaching electronswhile passing through the electron cloud in the neutralizing chamber.

[0006] In the case where the negative ions are neutralized by electronimpact, it is required to generate a high-density electron cloud inorder to obtain a high neutralization efficiency. However, since ahigh-density electron cloud is generated only in an extremely smallspace, the beam diameter of the neutral particle beam cannot be madelarger.

[0007] There has been known another neutral particle beam generatorwhich irradiates photons to a negative ion beam to detach electronstherein for thereby neutralizing the negative ion beam. In this neutralparticle beam generator, since a photon energy is larger than anelectron detachment energy from the negative ion beam, a highneutralization efficiency can be obtained without dependence upon theenergy of the negative ion beam.

[0008] In the case where the negative ions are neutralized byapplication of photons, a large light source and a large optical systemare required to make the beam diameter of the neutral particle beamlarger, resulting in a larger size of the apparatus. Only a slight partof light emitted from the light source contributes to neutralization,and the rest of light becomes heat loss. In order to obtain a highneutralization efficiency, the light source is required to have a higherfluence. However, the light source having a higher fluence needs acooling mechanism or the like, resulting in a larger size of apparatusand a higher cost of the equipments.

[0009] If a radiation (e.g., an ultraviolet ray) produced by the plasmain the neutral particle beam source is applied to the workpiece, thenthe radiation adversely affects the workpiece. Thus, it is necessary toshield the workpiece from an adverse radiation (e.g., an ultravioletray) emitted from the plasma source.

DISCLOSURE OF INVENTION

[0010] The present invention has been made in view of the abovedrawbacks. It is therefore an object of the present invention to providea neutral particle beam processing apparatus which can apply anenergetic beam having a large beam diameter to a workpiece with aninexpensive and compact structure, and can highly accurately perform aprocess such as an etching process or a deposition process on theworkpiece without a damage.

[0011] According to an aspect of the present invention, there isprovided a neutral particle beam processing apparatus, comprising: aprocess gas inlet port for introducing a process gas into a vacuumchamber; a plasma generating chamber for generating positive ions andelectrons from the introduced process gas; a negative ion generatingchamber for attaching the electrons generated in the plasma generatingchamber to the residual gas to generate negative ions; an ion extractingportion for extracting the positive ions or the negative ions andaccelerating the positive ions or the negative ions in a predetermineddirection; and a neutralization device for neutralizing an ion beamgenerated by the ion extracting portion to generate a neutral particlebeam, the neutral particle beam being applied to a workpiece.

[0012] With the above arrangement, a plasma composed of a large quantityof positive ions and electrons is generated in the plasma generatingchamber. In the negative ion generating chamber disposed downstream ofthe plasma generating chamber, the electrons which have lost energy bycollision while being delivered through the negative ion generatingchamber and have a lowered electron temperature are attached to theresidual gas, for thereby generating a large quantity of negative ions.Thus, negative ions can be generated with a simple structure. The ionsare extracted by the ion extracting portion and neutralized by theneutralization device, and hence a neutral particle beam can easily begenerated. With a processing apparatus using such a neutral particlebeam, various processes including an etching process and a depositionprocess can be performed on the workpiece with high accuracy in such astate that an amount of charge build-up is reduced.

[0013] According to a preferred aspect of the present invention, theneutral particle beam processing apparatus further comprises an electroncloud generator provided in the negative ion generating chamber forlowering the probability that the electrons collide with a sidewallsurface of the negative ion generating chamber and are inactivated andfor increasing the probability that the electrons attach to the residualgas.

[0014] With the above arrangement, a high-density negative ions can begenerated with increased efficiency. Further, a high-density neutralparticle beam can be generated by neutralizing such high-densitynegative ions.

[0015] According to a preferred aspect of the present invention, the ionextracting portion comprises a grid electrode and a power supply forbiasing the grid electrode to a positive or negative potential. Withthis arrangement, the negative ions generated in the negative iongenerating chamber or the positive ions generated in the plasmagenerating chamber can easily be extracted from the negative iongenerating chamber and neutralized to generate a neutral particle beam.

[0016] The neutralization device may comprise a light source forapplying a light ray to the ion beam, or may comprise an electrode and apower supply for applying a high-frequency electric field through theelectrode to the ion beam. The neutralization device may comprise anelectron beam radiation device for radiating an electron beam to the ionbeam, or may comprise an electron cloud generator for generating anelectron cloud along a path of the ion beam. Alternatively, theneutralization device may form a region where the pressure of gasmolecules is high within a path of the ion beam. The neutralizationdevice may comprise an orifice plate having orifices for allowing theion beam to pass therethrough.

[0017] According to the present invention, from a plasma having a largebeam diameter, it is possible to generate a neutral particle beam havingthe same diameter as the plasma without complicated mechanisms forgenerating negative ions, and to apply such a neutral particle beam tothe workpiece.

[0018] The above and other objects, features, and advantages of thepresent invention will be apparent from the following description whentaken in conjunction with the accompanying drawings which illustratespreferred embodiments of the present invention by way of example.

BRIEF DESCRIPTION OF DRAWINGS

[0019]FIG. 1 is a schematic view showing a whole arrangement of aneutral particle beam processing apparatus according to an embodiment ofthe present invention;

[0020]FIGS. 2A and 2B are cross-sectional views showing an example of anelectron cloud generator, and FIG. 2A is an axial cross-sectional view,and FIG. 2B is a radial cross-sectional view;

[0021]FIG. 3 is a fragmentary view showing an example of an ionextracting portion and a neutralizing device;

[0022]FIGS. 4A through 4C are schematic views showing various powersupplies connected to the ion extracting portion; and

[0023]FIGS. 5A through 5D are schematic fragmentary views showingvarious examples of the neutralization device.

BEST MODE FOR CARRYING OUT THE INVENTION

[0024] A neutral particle beam processing apparatus according to anembodiment of the present invention will be described in detail belowwith reference to FIGS. 1 through 5D.

[0025]FIG. 1 is a schematic view showing a whole arrangement of aprocessing apparatus according to a first embodiment of the presentinvention, with electric components in block form. As shown in FIG. 1,the processing apparatus comprises a cylindrical vacuum chamber 1 havinga process gas inlet port 11 for introducing a process gas into thevacuum chamber 1. The vacuum chamber 1 has a plasma generating chamber 2defined therein for generating positive ions and electrons from theintroduced process gas, a negative ion generating chamber 3 disposeddownstream of the plasma generating chamber 2 for attaching electronsgenerated in the plasma generating chamber 2 to the residual process gasto generate negative ions, and an ion extracting portion 4 forextracting the generated positive or negative ions and accelerating thegenerated positive or negative ions in a predetermined direction.

[0026] The vacuum chamber 1 also has a neutralizing chamber 5 definedtherein for neutralizing the extracted positive or negative ions, and aprocess chamber 6 defined therein for processing a workpiece X such as asemiconductor substrate, a glass workpiece, an organic workpiece, aceramic workpiece, or the like. The ions that have been extracted andaccelerated by the ion extracting portion 4 are neutralized in theneutralizing chamber 5 and converted into neutral particles. The neutralparticles are applied to the workpiece X in the process chamber 6. Thevacuum chamber 1 has walls made of quartz glass, ceramics, or the like.

[0027] The plasma generating chamber 2 has a coil 10 disposedtherearound for inductively coupled plasma (ICP). The coil 10 is housedin a water-cooled tube having an outside diameter of 8 mm, for example.The coil 10 of about two turns is wound around the plasma generatingchamber 2. The coil 10 is electrically connected through a matching box100 to a high-frequency power supply 101, which applies a high-frequencyvoltage having a frequency of about 13.56 MHz, for example, to the coil10. When a high-frequency current is supplied from the high-frequencypower supply 101 via the matching box 100 to the coil 10, an inducedmagnetic field is produced in the plasma generating chamber 2 by thecoil 10. The varying magnetic field induces an electric field. Theelectric field accelerates electrons, which ionizes atoms and moleculesin the process gas to generate a plasma in the plasma generating chamber2. Thus, the coil 10, the matching box 100, and the high-frequency powersupply 101 constitute a plasma generator for generating a plasma fromthe process gas in the plasma generating chamber 2. The generated plasmais mainly composed of positive ions and heated electrons which coexisttherein.

[0028] The gas inlet port 11 defined in an upper portion of the plasmagenerating chamber 2 is connected through a gas supply pipe 12 to a gassupply source 13, which supplies a gas such as SF₆, CHF₃, CF₄, Cl₂, Ar,O₂, N₂, and C₄F₈ to the plasma generating chamber 2.

[0029] The process chamber 6 houses a workpiece holder 20 therein forholding the workpiece X. The workpiece X is placed on an upper surfaceof the workpiece holder 20. The process chamber 6 has a gas outlet port21 defined in a sidewall thereof for discharging the gas from theprocess chamber 6. The gas outlet port 21 is connected through a gasoutlet pipe 22 to a vacuum pump 23, which operates to maintain theplasma generating chamber 2, the negative ion generating chamber 3, theneutralizing chamber 5, and the process chamber 6 at a predeterminedpressure.

[0030] In the negative ion generating chamber 3, electrons generated inthe plasma generating chamber 2 are attached to the residual gas togenerate a large quantity of negative ions. The plasma generatingchamber 2 and the negative ion generating chamber 3 are integrallycombined contiguously with each other, and the negative ion generatingchamber 3 is disposed downstream of the plasma generating chamber 2. Theprocess gas is continuously supplied into the plasma generating chamber2 from the upstream end of the plasma generating chamber 2, for therebycontinuously generating a plasma which is mainly composed of positiveions and electrons. The generated plasma is continuously delivered intothe negative ion generating chamber 3 disposed downstream of the plasmagenerating chamber 2. In the negative ion generating chamber 3,electrons which have lost energy by collision while being deliveredthrough the negative ion generating chamber 3 and have a loweredelectron temperature are attached to molecules or atoms of the residualgas, for thereby generating a large quantity of negative ions.Therefore, a plasma comprising a mixture of positive ions generated inthe plasma generating chamber 2, negative ions generated in the negativeion generating chamber 3, and electrons is generated in the negative iongenerating chamber 3.

[0031] The negative ion generating chamber 3 should preferably comprisean electron cloud generator for lowering the probability that electronscollide with the sidewall surfaces of the negative ion generatingchamber 3 and are inactivated and for increasing the probability thatelectrons are attached to the residual gas. FIGS. 2A and 2B show anexample of an electron cloud generator. FIG. 2A is an axialcross-sectional view, and FIG. 2B is a radial cross-sectional view. Asshown in FIGS. 2A and 2B, permanent magnets 31 are disposed around thenegative ion generating chamber 3 at predetermined circumferentialintervals. The permanent magnets 31 are arranged so that the magneticpoles of the adjacent permanent magnets are opposed to each other. Withthis arrangement, the permanent magnets 31 produce a magnetic field inthe negative ion generating chamber 3 as illustrated by lines 32 ofmagnetic force in FIG. 2B. Since electrons in the plasma move along thelines 32 of magnetic force, the electrons are prevented from contactingthe inner sidewall surface of the negative ion generating chamber 3.Thus, an electron cloud is formed at positions away from the innersidewall surface of the negative ion generating chamber 3. This electroncloud lowers the probability that electrons collide with the innersidewall surface of the negative ion generating chamber 3 and areinactivated, for thereby efficiently generating negative ions in thenegative ion generating chamber 3.

[0032] The ion extracting portion 4 for extracting positive or negativeions and accelerating the positive or negative ions in a predetermineddirection is provided downstream of the negative ion generating chamber3. The ion extracting portion 4 is constituted by a grid electrode 4,for example. The grid electrode 4 is connected to a power supply 8,which applies a positive or negative bias voltage to the grid electrode4.

[0033]FIG. 3 is a fragmentary view showing an example of the ionextracting portion 4, and FIGS. 4A through 4C show various powersupplies connected to the grid electrode 4. When an AC voltage isapplied to the grid electrode 4 by the power supply 8 a shown in FIG.4A, positive ions and negative ions are alternately extracted from thenegative ion generating chamber 3 and accelerated toward the downstreamneutralizing chamber 5. When a positive DC voltage is applied to thegrid electrode 4 by the power supply 8 b shown in FIG. 4B, positive ionsare extracted from the negative ion generating chamber 3 and acceleratedtoward the downstream neutralizing chamber 5. When a negative DC voltageis applied to the grid electrode 4 by the power supply 8 c shown in FIG.4C, negative ions are extracted from the negative ion generating chamber3 and accelerated toward the downstream neutralizing chamber 5.

[0034] In the example shown in FIG. 3, an orifice electrode (orificeplate) 41 is used as a neutralization device for neutralizing an ionbeam to generate a neutral particle beam. As shown in FIG. 3, theorifice electrode 41 has a number of orifices 41 a defined therein. Ionsaccelerated by the grid electrode 4 are introduced into the orifices 41a defined in the orifice electrode 41. Most of the ions that passthrough the orifices 41 a in the orifice electrode 41 are neutralized byexchanging electrons with the sidewall surfaces of the orifices 41 a, orby charge exchange with gas molecules remaining within the orifices 41a. Thus, the ions are converted into neutral particles.

[0035] The ions that have been neutralized when passing through theorifices 41 a, i.e., the neutral particles, are then emitted as anenergetic beam into the process chamber 6. The neutral particle beamtravels directly in the process chamber 6 and is applied to theworkpiece X placed on the workpiece holder 20, for thereby etching thesurface of the workpiece X, cleaning the surface of the workpiece X,modifying (e.g., nitriding or oxidizing) the surface of the workpiece X,or depositing a film on the workpiece X.

[0036] In the example shown in FIG. 3, the orifice electrode (orificeplate) is used as a neutralization device for neutralizing ions.However, the neutralization device is not limited to the illustratedexample. The present invention is also applicable to variousneutralization devices, e.g., neutralization devices shown in FIGS. 5Athrough 5D.

[0037] In an example shown in FIG. 5A, a light source is disposedoutside of the vacuum chamber 1 for applying light rays 42 to the ionbeam. In the neutralizing chamber 5, electrons are detached from ions,particularly negative ions, by energy of the light rays 42, and hencethe negative ions are neutralized.

[0038] In an example shown in FIG. 5B, a pair of electrodes 43 a, 43 bis provided in the vacuum chamber 1. One of the electrodes is connectedto a high-frequency power supply 44, which applies a high-frequencyelectric field to the ion beam which is passing between the electrodes43 a, 43 b. The negative ions of the ion beam are neutralized by thehigh-frequency electric field in the neutralizing chamber 5.

[0039] As shown in FIG. 5C, the neutralization device may comprise anelectron beam radiation device for radiating electron beams 45 into aneutralizing chamber 5 through a window 46 provided in the vacuumchamber 1. Alternatively, the neutralization device may comprise anelectron cloud generator for generating an electron cloud along a pathof an ion beam.

[0040] Further, as shown in FIG. 5D, the neutralization device maycomprise a gas inlet port 47 provided in the vacuum chamber 1 forintroducing a process gas or the like into the vacuum chamber 1. In FIG.5D, a region where the pressure of gas molecules is high is formedwithin a path of an ion beam, for thereby detaching electrons from ions,particularly negative ions, to neutralize the ions.

[0041] Operation of the neutral particle beam processing 5 apparatusaccording to the present embodiment will be described below.

[0042] The vacuum pump 23 is driven to evacuate the vacuum chamber 1.After the vacuum chamber 1 reaches a predetermined degree of vacuum, agas such as SF₆, CHF₃, CF₄, Cl₂, Ar, O₂, N₂, or C₄F₈ is introduced fromthe gas supply source 13 into the plasma generating chamber 2. Ahigh-frequency voltage having a frequency of about 13.56 MHz is appliedto the coil 10 by the high-frequency power supply 101, so that ahigh-frequency electric field is produced in the plasma generatingchamber 2. The gas introduced into the plasma generating chamber 2 isionized by electrons that are accelerated by the high-frequency electricfield, for thereby generating a high-density plasma in the plasmagenerating chamber 2. The plasma is mainly composed of positive ions andheated electrons.

[0043] The generated plasma which is mainly composed of positive ionsand heated electrons is delivered to the adjacent negative iongenerating chamber 3. In the negative ion generating chamber 3,electrons having a lowered electron temperature are attached to theresidual gas, for thereby generating negative ions. Thus, negative ionscan efficiently and continuously be generated from a plasma composed ofelectrons which have lost energy by collision while being delivered formthe upstream side and have a lowered electron temperature, positiveions, and the residual gas. While ordinary plasmas are mostly composedof positive ions and electrons, the neutral particle beam processingapparatus according to the present embodiment can efficiently generate aplasma in which positive ions and negative ions coexist therein.

[0044] The ion extracting portion (grid electrode 4) for extractingpositive or negative ions and accelerating the positive or negative ionsin a predetermined direction is provided downstream of the negative iongenerating chamber 3. A positive or negative bias voltage is applied tothe grid electrode 4 by the power supply 8. When an AC voltage isapplied to the grid electrode 4, positive ions and negative ions arealternately extracted from the negative ion generating chamber 3, thenaccelerated and emitted toward the workpiece X. Specifically, byproperly adjusting the polarity, magnitude, and frequency of theaccelerating voltage, positive and negative ions of desired energylevels are selectively or alternately extracted and applied to theworkpiece X.

[0045] The neutralization device (neutralizing chamber 5) forneutralizing ions to generate a neutral particle beam is provideddownstream of the ion extracting portion (grid electrode 4). In theneutralizing chamber 5, the positive ions are neutralized by attachmentof electrons in the plasma, by charge exchange with the residual gas, orby charge exchange with negative ions, and converted into neutralparticles. The negative ions are neutralized by detaching electrons inelectron impact, by charge exchange with the residual gas, or by chargeexchange with positive ions, and converted into neutral particles.Particularly, electrons are detached from the negative ions by aradiation (h ν), an electron beam radiation, or application of ahigh-frequency electric field, and the negative ions are converted intoneutral particles.

[0046] The negative ions or the positive ions that have beenneutralized, i.e., the neutral particles, are emitted as an energeticbeam into the process chamber 6. The neutral particles travel directlyin the process chamber 6 and are applied to the workpiece X placed onthe workpiece holder 20, for thereby etching the surface of theworkpiece X, cleaning the surface of the workpiece X, modifying (e.g.,nitriding or oxidizing) the surface of the workpiece X, or depositing afilm on the workpiece X. Particularly, since these neutral particles canbe generated from positive ions and negative ions at desired energylevels, the workpiece X can be processed flexibly.

[0047] As well known in the art, when an insulated workpiece such as aworkpiece made of glass or ceramics is processed, charge build-up may bedeveloped on the surface of the insulated workpiece. However, byapplying neutralized particles to the insulating workpiece as describedabove, various processes including an etching process and a depositionprocess can be performed on the insulating workpiece with high accuracyin such a state that an amount of charge build-up is reduced. Varioustypes of gases may be introduced into the plasma generating chamber 2according to the type of process to be performed on the workpiece X. Forexample, in a dry etching process, oxygen or a halogen gas mayselectively be used according to the kind of the workpiece X.

[0048] In the present embodiment, it is desirable to introduce a gasthat is liable to generate negative ions, such as O₂, Cl₂, SF₆, CHF₃, orC₄F₈, into the plasma generating chamber 2 so as to apply neutralparticles generated from the negative ions in the plasma. When theapplication of the high-frequency voltage is interrupted after ahigh-density plasma is generated by the aforementioned high-frequencyinductive coupling (ICP) with use of the above gas, a large number ofnegative ions can be generated and a neutral particle beam can begenerated from the generated negative ions.

[0049] In the present embodiment, the plasma is generated with use of acoil for ICP. However, the plasma may be generated with use of anelectron cyclotron resonance source (ECR source), a coil for heliconwave plasma, a microwave, or the like. The frequency of thehigh-frequency voltage is not limited to 13.56 MHz, but may be in therange from 1 MHz to 20 GHz.

[0050] In the above embodiment, the positive and negative ions extractedfrom the negative ion generating chamber by the ion extracting portionare neutralized and converted into neutral particles, and the neutralparticles are applied as a neutral particle beam to the workpiece.However, the positive and negative ions may directly be applied to theworkpiece without the neutralization device (neutralizing chamber).

[0051] Although certain preferred embodiments of the present inventionhave been shown and described in detail, it should be understood thatvarious changes and modifications may be made therein without departingfrom the scope of the appended claims.

Industrial Applicability

[0052] The present invention is suitable for use in a neutral particlebeam processing apparatus for generating a highly directional and highlydense neutral particle beam from a high-density plasma and processing aworkpiece with the generated neutral particle beam.

1. A neutral particle beam processing apparatus, comprising: a processgas inlet port for introducing a process gas into a vacuum chamber; aplasma generating chamber for generating positive ions and electronsfrom the introduced process gas; a negative ion generating chamber forattaching said electrons generated in said plasma generating chamber tothe residual gas to generate negative ions; an ion extracting portionfor extracting said positive ions or said negative ions and acceleratingsaid positive ions or said negative ions in a predetermined direction;and a neutralization device for neutralizing an ion beam generated bysaid ion extracting portion to generate a neutral particle beam, saidneutral particle beam being applied to a workpiece.
 2. A neutralparticle beam processing apparatus according to claim 1, furthercomprising an electron cloud generator provided in said negative iongenerating chamber for lowering the probability that said electronscollide with a sidewall surface of said negative ion generating chamberand are inactivated and for increasing the probability that saidelectrons attach to said residual gas.
 3. A neutral particle beamprocessing apparatus according to claim 1, wherein said ion extractingportion comprises a grid electrode and a power supply for biasing saidgrid electrode to a positive or negative potential.
 4. A neutralparticle beam processing apparatus according to claim 1, wherein saidneutralization device comprises a light source for applying a light rayto said ion beam.
 5. A neutral particle beam processing apparatusaccording to claim 1, wherein said neutralization device comprises anelectrode and a power supply for applying a high-frequency electricfield through said electrode to said ion beam.
 6. A neutral particlebeam processing apparatus according to claim 1, wherein saidneutralization device comprises an electron beam radiation device forradiating an electron beam to said ion beam.
 7. A neutral particle beamprocessing apparatus according to claim 1, wherein said neutralizationdevice comprises an electron cloud generator for generating an electroncloud along a path of said ion beam.
 8. A neutral particle beamprocessing apparatus according to claim 1, wherein said neutralizationdevice forms a region where the pressure of gas molecules is high withina path of said ion beam.
 9. A neutral particle beam processing apparatusaccording to claim 1, wherein said neutralization device comprises anorifice plate having orifices for allowing said ion beam to passtherethrough.